It is known to the art to incorporate active components such as enzyme into dry solid particles or granules and thereby protect the active component from inactivation and/or protect the environment from the active component. Many granules are composed of a core unit comprising an active component upon which one or more layers of coating is applied to improve properties such as enzyme stability, dust formation, colour, solubility rate etc. Various coating compositions are known in the art including salts, which for example are known within the detergent industry to protect enzymes against bleach present in the detergents.
WO 00/01793 discloses a substantially continuous layer or coating encapsulating the core comprising a water-soluble compound, such as an inorganic salt.
WO 99/32595 discloses a granule including a core and a hydrated barrier material with moderate or high water activity, such as a salt.
The object of the present invention is to provide an improved method for coating core units with salt. Salt-coatings are usually applied to core units as liquid compositions where the solvent, e.g. water, is evaporated after the application, thereby leaving the salt on the core unit as a coating. Often large amounts of water need to be evaporated as many salts used in coatings have a limited solubility in water. If higher concentrations of salt in the liquid composition are attempted significant recrystallization take place creating large salt crystals which tend to block nozzles, pumps and valves making it difficult to use the process on an industrial basis.
The present invention solves this problem by increasing the amount of dry matter in the liquid salt composition applied to the core unit without increasing formation of large salt crystals.